Solar energy has the potential to become a significant source of energy in the near future. However, high costs associated with active device materials have been an obstacle to their wide adoption. Material cost can be contained via the use of thin layers of active materials. In addition, thin-film photovoltaic cells have higher open-circuit voltages due to correspondingly lower recombination rates. Furthermore, such cells can be manufactured using considerably cheaper processes. The main drawback of such cells is their poor absorption of sunlight. Light trapping schemes have been proposed to increase the light absorption in their thin active layers. Some such schemes have included randomly textured surfaces applied on the top surface of the thin active layer. Light scattering from these textures increases the path length within the active material resulting in higher absorption. Such textures have typically been used with active layers several microns thick. Sub-micrometer grating structures on the bottom surface of the active layer have also been used to increase light absorption in such devices.